San Diego, California. Since alot of parts of San Diego are tourists spots they have nice inexpensive hotels near Seaworld but they also have great nightclubs, resturaunts and other romantic places by the beach to visit.
Honeymoons do not have to be expensive as long as they are romantic. Choose a cabin in the woods of Tennessee or Kentucky if you do not have the money to go to a fancy beach resort. You and your sweetheart can soak in the hot tub and you will have a wonderful time.